While retirement is a time most people slow down, Joe Sopher was busy working on an idea for a business. The popcorn fan was inspired by the flavours available in the US, and wondered if there might be an appetite for more quirky flavours back home.

“Dad used to work in the electrical world and would go to trade shows in America and bring back popcorn,” his son Adam Sopher, director at Joe & Seph’s, says. “There were always different flavours than those available in the UK. He retired and then started playing with recipes in the kitchen. I was bored working in my job and so the three of us [including Adam’s mother Jackie] decided there was an opportunity to launch a popcorn brand.”

Just three months later they were selling flavours such as goat’s cheese and black pepper at a trade show in London. “We thought we’d just see what everyone thought, and it just went mad. We sold out after day two.” A buyer from Selfridges saw the queue forming at their stand and asked for a meeting, resulting in an initial order of 300 bags in 2010. Fast forward to 2018, and the brand has grown its range to over 40 flavours, including gin and tonic and Marmite options. It is now stocked in 2,500 locations worldwide. The growing appetite for health-conscious snacks was a factor behind this success, Sopher says. “In our case, we don’t use oil, so it’s low in calories and fitted in nicely with the healthy consumer trend.”

It’s quite a change since toffee, salt, or sweet was the extent of the flavours you could expect to be served up at the local cinema.

Today, popcorn is ubiquitous; it’s bought as a lunch-hour snack or after a gym workout. The increase in availability and the appeal to the health-conscious consumer has meant the kernel has well and truly exploded: the UK popcorn sector was worth £152m last year, up 10% from 2016, according to Euromonitor, making the American snack the country’s fastest-growing grocery product.

Many of the brands leading this growth spurt are independent companies, like Joe & Seph’s.

Steph Croft-Simon, founder of Nom Foods, launched Nom Popcorn in 2015, which, she says, was the first organic popcorn brand in the UK. “I knew there was a market for popcorn that was simple, free from artificial flavours, and that wasn’t covered with refined sugar,” she says. However, it wasn’t easy. “It was difficult to track down an innovative manufacturer who could deal with the specific requirements of sourcing organic, ethical ingredients, and making sure that the production facility was gluten and dairy-free.”

Steph Croft-Simon, founder of Nom Foods Photograph: Nom Foods

After seeking advice and carrying out several trial runs, she launched with salted, salted maple and cinnamon maple flavours, each containing about 100 calories a bag. Now her popcorn is available from stockists such as Ocado, Whole Foods and Abel & Cole.

With big brands such as Metcalfe’s Food Company’s Skinny Popcorn and Tyrrell’s Poshcorn swooping in, the market for the snack has become crowded. But smaller players believe this brings added advantages. “Big brands have lots of money to spend on marketing their ranges, which is also great for us as they’re doing great work making popcorn a favourite go-to snack,” says Croft-Simon.

Sales of potato crisps have taken a hit, but have not yet been crushed by the rise of the kernel. “While popcorn has enjoyed phenomenal growth over the past five years, its market penetration is still a long way behind that of crisps,” says Anita Winther, Mintel food and drink analyst, who adds that popcorn is eaten by 34% of adults, compared to 81% for potato crisps. “It’s unlikely that popcorn will rival the popularity of crisps, which can be considered a British institution with a broad following across the generations.”

The popularity of popcorn here – the UK consumes twice as much popcorn as any other nation in Europe – has much to do with its versatility, in Croft-Simon’s view: “It can be eaten at all times of the day – we make popcorn granola for breakfast.” Brands are now expanding their ranges – Propercorn launched a range targeted at children last year. “While we’ve watched healthy snacking boom among adults, there remains a real need for healthier on-the-go alternatives for kids,” says Propercorn co-founder CassandraStavrou.

Winther believes popcorn and its innovative flavours are here to stay. “Young people eat savoury snacks the most and popcorn has made it on to their repertoire,” she says. “It is likely to remain there as they grow older.”